static struct vfsmount *inotify_mnt __read_mostly;
-/* this just sits here and wastes global memory. used to just pad userspace messages with zeros */
-static struct inotify_event nul_inotify_event;
-
/* these are configurable via /proc/sys/fs/inotify/ */
static int inotify_max_user_instances __read_mostly;
static int inotify_max_queued_events __read_mostly;
event = fsnotify_peek_notify_event(group);
- event_size += roundup(event->name_len, event_size);
+ if (event->name_len)
+ event_size += roundup(event->name_len + 1, event_size);
if (event_size > count)
return ERR_PTR(-EINVAL);
struct fsnotify_event_private_data *fsn_priv;
struct inotify_event_private_data *priv;
size_t event_size = sizeof(struct inotify_event);
- size_t name_len;
+ size_t name_len = 0;
/* we get the inotify watch descriptor from the event private data */
spin_lock(&event->lock);
inotify_free_event_priv(fsn_priv);
}
- /* round up event->name_len so it is a multiple of event_size */
- name_len = roundup(event->name_len, event_size);
+ /*
+ * round up event->name_len so it is a multiple of event_size
+ * plus an extra byte for the terminating '\0'.
+ */
+ if (event->name_len)
+ name_len = roundup(event->name_len + 1, event_size);
inotify_event.len = name_len;
inotify_event.mask = inotify_mask_to_arg(event->mask);
return -EFAULT;
buf += event->name_len;
- /* fill userspace with 0's from nul_inotify_event */
- if (copy_to_user(buf, &nul_inotify_event, len_to_zero))
+ /* fill userspace with 0's */
+ if (clear_user(buf, len_to_zero))
return -EFAULT;
buf += len_to_zero;
event_size += name_len;
list_for_each_entry(holder, &group->notification_list, event_list) {
event = holder->event;
send_len += sizeof(struct inotify_event);
- send_len += roundup(event->name_len,
- sizeof(struct inotify_event));
+ if (event->name_len)
+ send_len += roundup(event->name_len + 1,
+ sizeof(struct inotify_event));
}
mutex_unlock(&group->notification_mutex);
ret = put_user(send_len, (int __user *) p);
return error;
}
+/*
+ * Remove the mark from the idr (if present) and drop the reference
+ * on the mark because it was in the idr.
+ */
static void inotify_remove_from_idr(struct fsnotify_group *group,
struct inotify_inode_mark_entry *ientry)
{
struct idr *idr;
+ struct fsnotify_mark_entry *entry;
+ struct inotify_inode_mark_entry *found_ientry;
+ int wd;
spin_lock(&group->inotify_data.idr_lock);
idr = &group->inotify_data.idr;
- idr_remove(idr, ientry->wd);
- spin_unlock(&group->inotify_data.idr_lock);
+ wd = ientry->wd;
+
+ if (wd == -1)
+ goto out;
+
+ entry = idr_find(&group->inotify_data.idr, wd);
+ if (unlikely(!entry))
+ goto out;
+
+ found_ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
+ if (unlikely(found_ientry != ientry)) {
+ /* We found an entry in the idr with the right wd, but it's
+ * not the entry we were told to remove. eparis seriously
+ * fucked up somewhere. */
+ WARN_ON(1);
+ ientry->wd = -1;
+ goto out;
+ }
+
+ /* One ref for being in the idr, one ref held by the caller */
+ BUG_ON(atomic_read(&entry->refcnt) < 2);
+
+ idr_remove(idr, wd);
ientry->wd = -1;
+
+ /* removed from the idr, drop that ref */
+ fsnotify_put_mark(entry);
+out:
+ spin_unlock(&group->inotify_data.idr_lock);
}
+
/*
- * Send IN_IGNORED for this wd, remove this wd from the idr, and drop the
- * internal reference help on the mark because it is in the idr.
+ * Send IN_IGNORED for this wd, remove this wd from the idr.
*/
void inotify_ignored_and_remove_idr(struct fsnotify_mark_entry *entry,
struct fsnotify_group *group)
struct fsnotify_event *ignored_event;
struct inotify_event_private_data *event_priv;
struct fsnotify_event_private_data *fsn_event_priv;
+ int ret;
ignored_event = fsnotify_create_event(NULL, FS_IN_IGNORED, NULL,
FSNOTIFY_EVENT_NONE, NULL, 0,
fsn_event_priv->group = group;
event_priv->wd = ientry->wd;
- fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
-
- /* did the private data get added? */
- if (list_empty(&fsn_event_priv->event_list))
+ ret = fsnotify_add_notify_event(group, ignored_event, fsn_event_priv);
+ if (ret)
inotify_free_event_priv(fsn_event_priv);
skip_send_ignore:
/* remove this entry from the idr */
inotify_remove_from_idr(group, ientry);
- /* removed from idr, drop that reference */
- fsnotify_put_mark(entry);
-
atomic_dec(&group->inotify_data.user->inotify_watches);
}
kmem_cache_free(inotify_inode_mark_cachep, ientry);
}
-static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg)
+static int inotify_update_existing_watch(struct fsnotify_group *group,
+ struct inode *inode,
+ u32 arg)
{
- struct fsnotify_mark_entry *entry = NULL;
+ struct fsnotify_mark_entry *entry;
struct inotify_inode_mark_entry *ientry;
- struct inotify_inode_mark_entry *tmp_ientry;
- int ret = 0;
- int add = (arg & IN_MASK_ADD);
- __u32 mask;
__u32 old_mask, new_mask;
+ __u32 mask;
+ int add = (arg & IN_MASK_ADD);
+ int ret;
/* don't allow invalid bits: we don't want flags set */
mask = inotify_arg_to_mask(arg);
if (unlikely(!mask))
return -EINVAL;
- tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
- if (unlikely(!tmp_ientry))
- return -ENOMEM;
- /* we set the mask at the end after attaching it */
- fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);
- tmp_ientry->wd = -1;
-
-find_entry:
spin_lock(&inode->i_lock);
entry = fsnotify_find_mark_entry(group, inode);
spin_unlock(&inode->i_lock);
- if (entry) {
- ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
- } else {
- ret = -ENOSPC;
- if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
- goto out_err;
-retry:
- ret = -ENOMEM;
- if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))
- goto out_err;
-
- spin_lock(&group->inotify_data.idr_lock);
- ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,
- group->inotify_data.last_wd,
- &tmp_ientry->wd);
- spin_unlock(&group->inotify_data.idr_lock);
- if (ret) {
- if (ret == -EAGAIN)
- goto retry;
- goto out_err;
- }
+ if (!entry)
+ return -ENOENT;
- ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);
- if (ret) {
- inotify_remove_from_idr(group, tmp_ientry);
- if (ret == -EEXIST)
- goto find_entry;
- goto out_err;
- }
-
- /* tmp_ientry has been added to the inode, so we are all set up.
- * now we just need to make sure tmp_ientry doesn't get freed and
- * we need to set up entry and ientry so the generic code can
- * do its thing. */
- ientry = tmp_ientry;
- entry = &ientry->fsn_entry;
- tmp_ientry = NULL;
-
- atomic_inc(&group->inotify_data.user->inotify_watches);
-
- /* update the idr hint */
- group->inotify_data.last_wd = ientry->wd;
-
- /* we put the mark on the idr, take a reference */
- fsnotify_get_mark(entry);
- }
-
- ret = ientry->wd;
+ ientry = container_of(entry, struct inotify_inode_mark_entry, fsn_entry);
spin_lock(&entry->lock);
fsnotify_recalc_group_mask(group);
}
- /* this either matches fsnotify_find_mark_entry, or init_mark_entry
- * depending on which path we took... */
+ /* return the wd */
+ ret = ientry->wd;
+
+ /* match the get from fsnotify_find_mark_entry() */
fsnotify_put_mark(entry);
+ return ret;
+}
+
+static int inotify_new_watch(struct fsnotify_group *group,
+ struct inode *inode,
+ u32 arg)
+{
+ struct inotify_inode_mark_entry *tmp_ientry;
+ __u32 mask;
+ int ret;
+
+ /* don't allow invalid bits: we don't want flags set */
+ mask = inotify_arg_to_mask(arg);
+ if (unlikely(!mask))
+ return -EINVAL;
+
+ tmp_ientry = kmem_cache_alloc(inotify_inode_mark_cachep, GFP_KERNEL);
+ if (unlikely(!tmp_ientry))
+ return -ENOMEM;
+
+ fsnotify_init_mark(&tmp_ientry->fsn_entry, inotify_free_mark);
+ tmp_ientry->fsn_entry.mask = mask;
+ tmp_ientry->wd = -1;
+
+ ret = -ENOSPC;
+ if (atomic_read(&group->inotify_data.user->inotify_watches) >= inotify_max_user_watches)
+ goto out_err;
+retry:
+ ret = -ENOMEM;
+ if (unlikely(!idr_pre_get(&group->inotify_data.idr, GFP_KERNEL)))
+ goto out_err;
+
+ spin_lock(&group->inotify_data.idr_lock);
+ ret = idr_get_new_above(&group->inotify_data.idr, &tmp_ientry->fsn_entry,
+ group->inotify_data.last_wd,
+ &tmp_ientry->wd);
+ spin_unlock(&group->inotify_data.idr_lock);
+ if (ret) {
+ /* idr was out of memory allocate and try again */
+ if (ret == -EAGAIN)
+ goto retry;
+ goto out_err;
+ }
+
+ /* we put the mark on the idr, take a reference */
+ fsnotify_get_mark(&tmp_ientry->fsn_entry);
+
+ /* we are on the idr, now get on the inode */
+ ret = fsnotify_add_mark(&tmp_ientry->fsn_entry, group, inode);
+ if (ret) {
+ /* we failed to get on the inode, get off the idr */
+ inotify_remove_from_idr(group, tmp_ientry);
+ goto out_err;
+ }
+
+ /* update the idr hint, who cares about races, it's just a hint */
+ group->inotify_data.last_wd = tmp_ientry->wd;
+
+ /* increment the number of watches the user has */
+ atomic_inc(&group->inotify_data.user->inotify_watches);
+
+ /* return the watch descriptor for this new entry */
+ ret = tmp_ientry->wd;
+
+ /* match the ref from fsnotify_init_markentry() */
+ fsnotify_put_mark(&tmp_ientry->fsn_entry);
+
+ /* if this mark added a new event update the group mask */
+ if (mask & ~group->mask)
+ fsnotify_recalc_group_mask(group);
+
out_err:
- /* could be an error, could be that we found an existing mark */
- if (tmp_ientry) {
- /* on the idr but didn't make it on the inode */
- if (tmp_ientry->wd != -1)
- inotify_remove_from_idr(group, tmp_ientry);
+ if (ret < 0)
kmem_cache_free(inotify_inode_mark_cachep, tmp_ientry);
- }
+
+ return ret;
+}
+
+static int inotify_update_watch(struct fsnotify_group *group, struct inode *inode, u32 arg)
+{
+ int ret = 0;
+
+retry:
+ /* try to update and existing watch with the new arg */
+ ret = inotify_update_existing_watch(group, inode, arg);
+ /* no mark present, try to add a new one */
+ if (ret == -ENOENT)
+ ret = inotify_new_watch(group, inode, arg);
+ /*
+ * inotify_new_watch could race with another thread which did an
+ * inotify_new_watch between the update_existing and the add watch
+ * here, go back and try to update an existing mark again.
+ */
+ if (ret == -EEXIST)
+ goto retry;
return ret;
}
spin_lock_init(&group->inotify_data.idr_lock);
idr_init(&group->inotify_data.idr);
- group->inotify_data.last_wd = 0;
+ group->inotify_data.last_wd = 1;
group->inotify_data.user = user;
group->inotify_data.fa = NULL;
git.openpandora.org / pandora-kernel.git / blobdiff